Conchomorph (Snail)
Conchomorphs, or snails, are one of the four original biomorph types in the original version of Blind Watchmaker. The bodies of conchomorphs resemble those of molluscs, such as whelk, abalone, or snail. Remarkably for their lifelike appearance, the coded definition of the conchomorph genome is the most compact of all of the biomorph genomes, consisting of only a few genes which determine the overall geometry of the conchomorph's body (its 'shell', in the specialised language of conchomorphology), with an optional extra gene which specifies the shape of the shell's cross section, its generating curve (the cross section is an oval otherwise.)
The simplicity of the genome's definition, however, is deceptive. The principal genes of the conchomorph genome are of 'real' data type, meaning they can take on fractional values, unlike the vast majority of the other three classic biomorph species. Additionally, the extra geometrical outline gene actually does represent quite a bit of genomic information, as it is equivalent to a long list of line segments describing the outline of the snail's opening. Dawkins provided fifteen sample conchomorph outline curves, each a black outline drawn on a transparent background, and ranging, in their maximum dimension up to 259 pixels in size. There is no practical limit to the number of possible generating curves, so the complexity of the conchomorph genome, in comparison to the other classic biomorph genomes is very much greater than the simplicity of its specification might at first suggest. If we were only to allow generating curves to fill a square no more than 256 pixels on a side, the generating curve occupies as much as 8 kilobytes of storage, which is in the neighborhood of the size of some of the genes in living cells.
The implementation of conchomorphs in Blind Watchmaker does not breed new generating curves as mutant offspring of ancestral ones, but implementation of such an algorithm would be be relatively trivial, especially if the generating curve is represented as a sequence of connected line segments.